On 01/09/2014 01:58 PM, Ian Malone wrote:
Latest installed is almost exactly not what you want, I've had plenty
(where plenty in this case is probably >5) of cases where a kernel
update broke something, in quite a few of those cases to a state where
the system wouldn't boot. If the most recent one is retained then
you've still got a kernel, but not one that will actually run. With
current behaviour I can still let my system update until a fix appears
because I know it won't remove the good kernel. If updates can remove
the running kernel then you have to watch each one carefully. 
Right, so if you run into a situation where you need to run an old kernel-0.99, you'd protect it
with /etc/yum/protected.d/kernel-0.99.conf , assuming that yum allows specifying package version as well as the name.

By the way, currently the protected list seems to beĀ  'yum, systemd and running kernel'. I don't have a system to try it on, so I just hope that one can't delete their dependencies either (glibc? what else?). I think you can still brick the system with careless yum erases: for instance, deleting grub.

That's why I like the approach of explicitly protecting against removal via .conf files---even though I don't see how to preserve the protection of the currently running kernel in this scheme.